Blasting apparatus



'(No Model.) I

M. JOHN 8v G. BRADLB BLASTING APPARATUS. I No. 249,841. Patent ed Nov. 22,1881.

- UNITED STATES PATENT OFFICE.

MATTHEW JOHN AND GEORGE BRADLEY, 0F PITTSTON, PENNSYLVANIA.

- BLASTING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 249,841, dated November 22, 1881.

Application filed July 22,1880. Renewed October 10,1881. (No model.)

To all whom it may concern:

Be it known that we, MATTHEW JOHN and GEORGE BRADLEY, of Pittston, in the county of Luzerne and State of Pennsylvania, have invented certain Improvements in Blasting Apparatus, of which the following is afull,

clear, and exact description.

Our invention has for its object to explode charges of blasting powder with less risk, greater certainty, and by the use of less powder than heretofore.

In the drawings forming part of this specification, Figure 1 is a view illustrating the ordinary mode and appliances for exploding blasts in coal-mines. Fig. 2 is aview illustrating our improved appliances and the mode of applying the same. Fig. 3 is an enlarged view of the blasting barrel, cartridge, and needle; and Fig. 4 is amodification.

In the ordinary mode of exploding charges in coal-mines a cartridge, A, is tied to a blasting-tnbe, 13. Both are inserted in the bore a, the mouth of which, around the blasting-tube, is packed, as shown at y, A squib, c, is then passed through the tube to the cartridge, and is ignited at the outer end, the fire working gradually back to the cartridge, which is thus exploded. But little difficulty results from these operations where the bore does not cross seams through which gas can pass under pressure; but when this is the case, which is almost invariable when the mine is deep, the gas, passing into the bore, permeates the cartridge, and thus reaches the barrel, through which it rushes, often with such force as to blow forward the fire and render it difficult to ignite the charge.

Frequently the gas is intermittent in its action, and after blowing forward the fire the structed to fit in the tube.

pressure will be reduced and the fire permitted to reach the cartridge, often exploding the latter at a time when the workmen have supposed the fire to be exhausted, thus causing' frequent and serious accidents. To avoid these results we stop up the end of the blasting-barrel with powder or fulminate, preferably carried by a capsule. This capsule may be of any required shape. For instance, it may be a cap, D, having fulminatej'at the end, as shown in Fig. 3; or it may be filled with powder, as shown in Fig. 4; or it may be con- After the capsule is secured to the blasting-barrel it is inserted intothe cartridge, which is then securely tied to the barrel in the usual manner. The barrel and cartridge are then inserted into the bore,

the latter is packed or tamped in the usual manner, and a slow-match, c, and a squib or quick-match, d, are inserted into the outer end of the barrel B. The slow-match is ignited, and ignites the quick-match or squib d, which shoots inward and ignites the powder or fulminate of the capsule D, which is exploded, thereby igniting the charge in the cartridge A.

By stopping up the outlet, as described, the gas is accumulated under pressure behind the tamping y, and we have found that a much more efl'ective explosion is secured by the'same amount of powder where pressure is used than if the explosion were not under pressure; also, by the appliances described, a certainty of explosion is secured, as well as much greater safety in operating the apparatus.

In order to insure greater certainty in exploding the capsule, we useaneedle, I, sharpened at the end, to break up orloosen the fulminate, as shown in Fig. 3, prior to the introduction of the matches, so that the fire can more readily ignite the particles of fulminate than when the same are packed closely together. This needle may be barbed at the end, so that it may be employed to withdraw spent squibs from the barrel where the powder is damp or the squibs fail to ignite.

We do not limit ourselves to the precise mode-described of using an explosive fulminate or mixture for scaling up the end of the barrel, as other means will readily suggest themselves.

We claim- 1. In a blasting apparatus, the combination, with a cartridge pervious to gas, of .a barrel, B, having its inner end sealed by any suitable explosive material, substantially as set forth.

2. The combination, with the cartridge, of

the barrel B, adapted to receive the slow and quick matches, and the capsuleD, containing an explosive mixture, and adapted to the end of the barrel, substantially as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

Witnesses:

I. E. JAMES, L. B. ENSIGN. 

